Hose clamp structure



De@ 16, 1952 T. B. TRESIDDER Erm. 2,521,383

HOSE CLAMP STRUCTURE Filed May 20, 1948 Patented Dec. 16, 1952 HOSE CLAMP STRUCTURE Thomas Bruce Tresidder and Alan Eynsford Moore, Melbourne, Victoria, Australia Application May 20, 1948, Serial No. 28,108 In Australia May 27, 1947 19 Claims.

This invention relates to an improved hose clip and it refers particularly to a clip adapted to be used for the purposes of tensioning a band or strap which is placed about the end portion of a flexible hose in such manner that the ilexible hose will be tightly clamped about and securely fastened to a rigid pipe or connector. In this specification the term hose clip is used to denote the device for tensioning the strap about the hose.

Such hose clips are well known and they are used extensively in automobiles for the purpose of fastening radiator hosing to connectors on 'the cylinder blocks and radiators, and they are employed in aircraft for securing iiexible pipes for petrol, hydraulic, pneumatic and other iiuid systems or installations to the appropriate ttings. In general the method of iitment is the same for all applications; the end of the flexible hose-which is of appropriate internal diameter-is slid over the end of a connector and a flexible strap, which is used in conjunction with the hose clip, is passed about the end portion of the hose. The opposite ends of the strap are connected to the hose clip and a tensional stress is applied to the strap by the hose clip so that the strap will be strained circumferentially, thereby exerting a compressive force radially inwards on the hose to increase the frictional grip between the external surface of the connector and the internal surface of the hose. The radial force required to be applied to the hose will, of course, depend uponthe internal pressure which the hose is required to withstand and/or the tensional force which may be applied to the hose. I

The internal pressures of automobile radiator systems are not very 'high sor/that the principal Vfactors to be considered in selecting asuitable hose clip are those of economy of production vand convenience of installation. But, in some vinstances,r the pressures employed in aircraft vflexible pipe installations are relatively high. Moreover, in View of the safety requirements, itis necessary in aircraft installations to provide efficient connection means which will be congsistent in their operation. Therefore the principal factor to be considered, in aircraft use, is that of clamping efficiency, although the factor of convenience of installation is also ci irnportance. I Y' f It is also to be observed that, in orderto ensure maximum emciency of operation of the hose clips hitherto available Vforruse in aircraftit has .been `:the practice f 'to gprohbit the vrepeatef'i aise of a hose clip. Thus if for any reason a hose clip and strap be removed then that clip cannot be replaced in position but must be discarded and a new clip and strap substituted. This, of course, results in a relatively high usage of clips and straps during the life of an aircraft.

This invention has been devised principally with the object of providing a hose clip which will have a high degree of eiiiciency in operation. An important factor in considering efflciency is the proportion of the circumference of the hose which is gripped and radially compressed by the hose clip and strap. A dependent object, therefore, is to provide a hose clip which, with the strap, will exert radial pressure upon substantially the entire circumference of a nexible hose to which it is tted.

A further object is to devise a hose clip which will be convenient to lt in position with the flexible strap and will be readily operated so as to tightly clamp a hose end on to a connector.

A still further object is to produce a hose clip of relatively economical construction which will possess the advantage that it will not be necessary to discard the clip whenever a hose clip is removed from an aircraft flexible tube installation, it being desired to retain as much of the combined hose clip and strap as possible so that the cost of replacement of the hose clip fittings after an overhaul of an aircraft will be considerably reduced. Y

Yet another object is to provide ahose clip which Will have a greater range of application so that the one size of hose clip may be conveniently used for a large variety of sizes of ilexible hosing, thereby reducing tooling, production and servicing costs. Y

With these and other objects in view we have devised a hose clip which possesses the following advantages: the strap fitting about the end portion of the flexible hose is strained circumferentially by a substantially radial movement and it is held in contact with the flexible hoserfora relatively large proportion of the circumference thereof; that portion of the flexible hose .which is not engaged by the strap is'acted upon radially by the base of the hose clip to which the opposite ends of the strap are connected; the'olamping of the opposite ends of the strapvv and the tensioning thereof may bev effected by finger pressure only; and to replace a hosevclip-i-ltting after use it is merely necessaryto substitute a new strap for that discarded, the hose clip being retained. v Y

The hose clip provided by our vinvention ccmprises a housing and a clamp associated with the housing, the clamp being adapted to securely fasten together the opposite ends of a flexible metal band or strap. The clamp is connected to the housing by a screw in such manner that when the screw is operated to tension the strap there is caused a relative movement between the clamp and the housing so that the clamp moves substantially radially outwards relative to side members of the housing. Thereupon the opposite ends of the strap are drawn outwardly to tension the strap, the end portions of the strap moving slidably about the inner edges of the side members of the housing and being held thereby rmly in contact with the outer surface of the flexible hose. Simultaneously, a portion o1" the housing is pressed radially inwards to act upon that portion of the hose which is not gripped by the strap.

In order that the invention will. be clearly understood and the advantages thereof fully appreciated reference lwill now be made to the accompanying sheet of illustrative drawings which depict an exemplary form of hose clip constructed according to this invention, and a minor modification thereof. In these drawings:

Fig. 1 shows a hose clip, constructed according to our invention, associated with a flexible strap and tted on to a flexible hose so as to clamp it on to a connector, l

Fig. 2 is a transverse section or" the hoseclip assembly in initial position prior to the clamping ofthe opposite ends of the strap.

` Figs. 3 is a section, similar to Fig. 2, but with the ends of the strapV securely held in the clip.

Fig. 4 shows the hose clip in transverse section, the clip being drawn upwardly to tension the strap.

the strap 8. The sides I8 are further strengthened by the embossments I9.

Located within the parts II and i2 is the cage I3. This cage is of substantially rectangular shape and it is formed by folding a length of metal so that its opposite ends project upwardly and theninwardly to form an open rectangular box or cage. For purposes of strength the opposite ends are folded so as to overlap. The overlapping ends 21 are drilled and tapped at 28 to constitute a nut and the underneath portion or base of the cage is drilled at 29 axially Ywiththe tapped hole 23. The screw Il is tted f through.the central hole in the embossed top I Fig. 5 illustrates, `in longitudinal section, a

slightly modied form of the invention.

Referring initially to Vthe construction illustrated mand by Figs. 1 to e', the hose clip fitting consists of the combination of a hose clip, indicated in Fig. 1 by the letter A, and a strap B. The strap fits tightly about a hose C which is to be secured to a connector D.

The hose clip A, which constitutes the principal part ofY this invention, consistsof a housing II, a

base I2, a cage I3, a screw It and a wing-nut I5. The housing II has a top plate I5 embossed and ribbed at Is'I and formed with acentral hole, two rectangular-shaped sides I8 embossedat I9, and two v`ends `20 of broadly V shape. The opposite edges of the sides I8 are cut away at The base I2 comprises an arcuately curved base plate 22 formed withtwo upwardly extending ends 23. Eachfof these ends has, near its inner end, two oppositely positioned inturned lugs 24, and, in its outerv end portion, a narrow slot 25. The housing II and base I2 are adapted to-.intert, with the ends 23 of the base I2r sliding between the ends 2Q of the housing I I and the lugs 24 of the base fitting slidably about thecutaway edges 2l of the housing sides I8. The ends 20 of the housing II are formed atZG. with inward projections which engage in the slots 25 of the base I2 and limit the relative movement of the housing II and base I2. A

By reason of the interlocking design of v these two parts the composite-structure is extremely strong. Thus, the lugs 2li fitting about the opposite edges of the sides I 8 restrain those sides against outward movement under the tension of of the housing II so as to engage in the tapped hole 28 of the cage I3, the wing nut I5 being first engaged on the screw I4 so that it is adapted to bear on the embossment Il. The outer end of the screw I4 isflattened at Si) to form a large head capable of being conveniently gripped by the lingers. The inner end of the screw lil is rounded slightly so that it is adapted to press the metal of the strap B into the drilled hole 2i).

In order to engage `the ends of the strap B in the clamp formed by thecage I3 and screw Ill the screw is loosened until there is sufficient clearance between the inner end of the screw I and the base of the cage I3. The opposite ends of the strap B are then inserted between the lower ends of the sides I3 and the base plate 22 so as to project into and through the cage iii-see Fig. 2. The screw I4 is then turned so that it presses on the end portions of the strap B, and, by'further rotation, forms indentations in the strap by forcing the material thereof into the hole 29 which is formed in the base of the cage I3. The ends of the strap B will then be rmly gripped in the cage ISby the screw Il-see Fig. 3. It is to be noted that the material of the strap B is not perforated or cut, so that its maximum strength is retained. i y

The strap B may b e tensioned by turning the wing nut I5 so that the screw lli is drawn outwardly ofthe housingV I I. lWith the initial rotation of the wing nut I5 the housing II is pressed downwardly relative to the cage I3, due tothe relative ease with which the strap B is bent. After a short movement the cage I3 will commence to move radially outwards as the housing Il moves inwardly, the forces acting on the two parts tending to balance, and then as the strap Bis further tensioned-ifthe housing II has reached the limit ofits inward movementthe cage I3 will be drawn outwardly, pulling the end portions of the strap B beneath the sides I8 of the housing I I--see Fig. 4.

As the tensional stress of the strap B increases it compresses the Amaterial of the flexible hose C and, acting together with the inward pressure of the base I2, increases the pressure with which the connector D is gripped, with the result that the frictional loading to prevent escape of fluid and/or to restrain the hose C from becoming disconnected from the connector D is gradually increased until it is sufhcient to withstand the internal pressures of the tube C and/or the tensional stresses tending to pull the tube C from the connector D. Y

According to themodiflcation depicted in Fig. 5 the ends 20 of the housing II are slotted at 3I and the upper or outer extremities of the ends 23 of the'base I2V are formed `as outwardly projecting tongues. .32j adapted to engage slidably in the slots 13|. AThus the-slotv-and-pin connection of the construction illustrated in Figs. l to 4 is reversed. The construction shown in Fig. 5 is, in other respects, similar to that shown in Figs. 1 to 4. In this view the folded construction of the cage I3 is clearly illustrated.

By reason of the fact that the strap B may be readily cut to any convenient length from a roll of suitable material, and as the curvature of the base plate 22 is selected to correspond with diameter of flexible hose approximately the mean of the hosings to which the hose clip may be applied, it will be found that the one size of hose clip A may be conveniently and efficiently used for a very large range of diameters of flexible hosing. The parts of the hose clip A are so designed that the tensioning movements of the several parts are su'icient to apply a loading suitable for the range selected and to withstand the desired internal working pressures customarily applied to hoses within that range.

The hose clip A is of very sturdy, compact construction and the parts are relatively economical to manufacture. The strap B is made of a metal having desired properties of tensile strength, flexibility and hardness and it may be cut to the desired width from sheets of suitable material. The housing il, base I2, and cage I3, of the hose clip A may all be conveniently formed by metal pressing operations.

What we do claim is:

1. A hose clamp structure comprising a strap f adapted to encircle a hose, a clamping device including an operating screw clamping the end portions of said strap together in circumferentially lapped relation, a housing provided with a base which is adapted to press upon the surface of t the hose underneath said clamping device, said clamping device being outwardly movably associated with said housing whereby said strap may be tensioned, and means having threaded engagement with said screw and bearing on said housing for drawing said clamping device and the strap end portions clamped together thereby outwardly with respect to said housing, said housing being formed with side walls to bear against and to retain the portions of said strap at opposite sides of said base against the hose which said strap is adapted to encircle.

2. A hose clamp structure according to claim 1 wherein said housing has openings formed under its opposite side walls so that the end portions of said strap may be passed through such openings for clamping in said clamping device.

3. A hose clamp structure according to claim l wherein said clamping device consists of a cage to receive the end portions of said strap and said screw is in threaded engagement with said cage for clamping together the end portions of said strap.

4. A hose clamp structure according to claim 3 wherein said screw and a nut threaded thereon and bearing on said housing constitute said means for drawing said clamping device outwardly with respect to said housing.

5. A hose clamp structure according to claim 4 wherein said cage has upper and lower sides between which the lapped end portions of said strap are disposed, the upper side being formed with a threaded hole therethrough for said screw, and the lower side being formed with an opening in alignment with such threaded hole whereupon turning of said screw causes the end thereof to form indentations in the lapped portions of said strap.

6. A hose clamp structure comprising a strap adapted to encircle a hose, a clamping device including an operating screw clamping together in circumferentially lapped relation the end portions of said strap, a tensioning device including a housing member embracing the lapped portions of said strap and a base member connected to said housing member, said base member being disposed underneath the lapped end portions of said strap, said members forming therebetween and at opposite sides openings to receive the lapped end portions of said strap, and a nut threadedly connected to the screw of said clamping. device and bearing on said housing member to draw said clamping device and the lapped end portions of said strap clamped together thereby with'respect to` said housing and base members and thus to tensionsaid strap about a hose 7. A hose clamp structure according to claim 6 wherein one of said housing and base members is formed with lugs engaging the sides of the other one of said members to resist spreading apart of the opposite sides of said housing member under the tension of said strap.

8. A hose clamp structure according to claim 7 wherein said lugs are formed near the inner end portions of the opposite sides of said base member and are inturned to it about the edge portions of the sides of said housing member.

9. A hose clamp structure according to claim 6 wherein the housing member has a projection formed on each of its opposite end Walls and the base `member has a vertical slot formed in each of its opposite end walls at such a location that the projections of the housing member are adapted to t slidably Within the slots of the base member.

10. A hose clamp structure according to claim 6 wherein the base member has a projection formed on each of its opposite end walls and the housing member has a vertical slot formed in each of its opposite end walls at such a location that the projections of the base member are adapted to fit slidably within the slots of the housing member.

11. A hose clamp structure according to claim 6 wherein said screw extends through a hole in said housing member, and said nut is threaded onto said screw and bears on said housing member.

l2. A hose clamp structure according to claim 11 wherein said screw is threaded into a hole formed in said clamping device and presses upon and clamps the lapped end portions of said strap together.

13. A hose clamp structure according to claim 12 wherein said clamping device comprises a cage formed with a screw-threaded hole in its upper surface for said screw and a coaxial hole in its lower surface whereby indentations are formed in the lapped end portions of said strap to securely clamp such portions in said cage.

14. A hose clamp structure according to claim 13 wherein said nut is threaded onto the outer end of said screw to bear against the top of said housing member whereby upon rotation of said Y nut, said screw and thus said cage with the lapped end portions of said strap clamped therein are drawn outwardly relative to said housing member.

15. A hose clamp structure for tensioning a flexible strap about a hose comprising a clamping device and a tensioning device; said clamping device consisting of a screw and a clamping member threadedly engaged with said screw and formed to receive the end portions of a strap in overlapped relation for clamping together between said .screw and clamping member, said tensioning defv'fi'ce consisting of a housing meinb'e having a holev through the top through which said screw extends and opposite depending side walls straddling said clamping member, a base member having a base plate underneath said clamping member and opposed opstanding walls, each of which is formed with a lug at each of its opposite sides to embrace, and thus preclude transverse spreading apart of the side Walls of said housing member, and means threadedly engaged with said screw and bearing on the top of said housing member for drawing said clamping device toward the top of said housing member and away from said base plate.

n 16.21 hose clamp structure according to claim 15 wherein said screw is formed with a fingerpiece at its outer end and said means comprises a wing nut, the hole in the top of the housing member being unthreaded for permitting drawing of said screw as aforesaid.

17. A hose clamp structure according to claim 16 wherein said base plate is curved arcuately to fit around a portion of the periphery of the hose.

18. A hose clamp structure according to claim l wherein the clamping member comprises a cage formed with end walls and upper and lower surfaces, the opposite sides being open to permit the fitting of the ends of a flexible strap into the cage, a, screw-threaded hole being formed in the upper surface of the cage and a, hole being formed in the lower surface of the cage in axial alignment with the first-mentioned hole, the screw being engaged in the screw-threaded hole in said cage.

8 19. Strap end gripping and tensioning means comprising a clamp device including an operating screw and adapted to engage the grip opposed overlapping strap end portions, and a housing for said clamp provided with a top wall through which said screw extends and with opposed side walls adapted to engage the strap portions to each side of the clamped. overlappingl end portions, and a nut bearing against such top Wall of said housing and threadedly engaging said screw whereby said clamp device and the clamped overlapped end portions of the strap may be drawn into said housing toward such top Wall thereof.

THOMAS BRUCE 'IRESIDDER ALAN EYNSFORD MOORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Austin Mar. 6,

FOREIGN PATENTS Country Date Germany May 23, 1921 Switzerland Feb. 1, 1945 Date 18, 11, 11, 18,

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